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Sage-grouse (Centrocercus spp.) were abundant in all of Utah's 29 counties at the time of European settlement wherever sagebrush (Artemisia spp.) occurred. Greater Sage-Grouse (G. urophasianus) inhabited areas north and west of the Colorado River, and Gunnison Sage-Grouse (G. minimus) occupied suitable habitat south and east of the Colorado River. The largest Greater Sage-Grouse populations in Utah are currently restricted to suitable habitats in Box Elder, Garfield, Rich, Uintah, and Wayne Counties. A remnant breeding population of Gunnison Sage-Grouse occurs in eastern San Juan County. We stratified Greater Sage-Grouse populations (1971-2000) by counties where the 1996 to 2000 moving average for estimated spring...
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First paragraph of introduction: On 20 July 2004 a single Asian tapeworm (Bothriocephalus acheilognathi) was collected from the intestine of a roundtail chub (Gila robusta) in the Yampa River in Dinosaur National Monument in northwestern Colorado. This fish (274 mm TL) was collected at river mile 24 and dissected in the field. A single tapeworm was removed from the intestine and preserved in ethanol. The tapeworm was later identified in the laboratory as B. acheilognathi by its characteristic arrow-shaped scolex (Poole et al. 1984). This is the 1st recorded incidence of Asian tapeworm infecting fish in the Yampa River drainage. Published in Western North American Naturalist, volume 65, issue 3, on pages 403 - 404,...
Discovery of distinct mid-elevational bands of blackbrush (Coleogyne ramosissima Torr.) shrublands on desert mountain slopes in the Mojave Desert caused an investigation of the relationships between environmental factors and Coleogyne distribution. Environmental factors were quantitatively examined to determine which were significant predictors of Coleogyne density at upper-elevational limits (ecotones) in the Spring Mountains of southern Nevada. Path analysis revealed significant, direct causal effects of air temperature, soil moisture, soil depth, and percent litter cover on the distribution of Coleogyne. Specifically, air temperature was a significant positive predictor, while soil moisture, soil depth, and percent...
Plant macrofossils from packrat middens in two southeastern Utah caves outline development of modern plant zonation from the late Wisconsin. Allen Canyon Cave (2195 m) and Fishmouth Cave (1585 m) are located along a continuous gradient of outcropping Navajo Sandstone that extends from the Abajo Mountains south to the San Juan River. By holding the site constant, changes in the floral composition for a plot of less than one hectare can be observed, even if sporadically, over tens of millennia. At Allen Canyon Cave, Engelmann spruce-alpine fir forest was replaced by the present vegetation consisting of pinyon-juniper woodland on exposed ridgetops and cliffside stands of Douglas fir, ponderosa pine, and aspen. Xerophytic...
Five alcoves (rock shelters) in the Forty-Mile Canyon—Willow Gulch area of the Escalante River Basin in southeastern Utah yielded rich deposits of late Quaternary macrobotanical remains. The deposits were sampled and the contents identified in order to construct a chronology of vegetational change. Fourteen radiocarbon dates indicate that the fossils were deposited between 12,690 and 7510 yr B.P. (years before present). Ninety-one plant taxa were identified, 62 to species. Six species were common to all alcoves: Gambel oak (Quercus gambelii), box-elder (Acer negundo), prickly pear (Opuntia subgenus Platyopuntia), skunkbush (Rhus aromatica var. trilobata), serviceberry (Amelanchier utahensis), and Indian ricegrass...
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Forests of the southern Rocky Mountains are punctuated by persistent meadows called parks that are dominated by grasses and forbs. In an attempt to elucidate the maintenance of subalpine parks in the Gunnison Basin, Colorado, soil texture and tree morphology differences along 60-m transects spanning the forest-park ecotone were studied in 6 representative parks. Seedling survivorship, percent seed germination, and soil moisture available to plants were also studied along one of the transects in Willow Park. Soil analyses revealed 40% more silt and significantly less sand and clay in all 6 parks (P < 0.001), which supports the traditional hypotheses that edaphic factors are involved in restricting establishment of...
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Resource specialists at Dinosaur National Monument utilize both planned and unplanned wildland ignitions in big sagebrush (Artemisia tridentata)--dominated plant communities to restore successional processes, maintain vegetation vigor, and promote diversified landscapes. Short- and long-term effects of prescribed burning on small mammal populations are not well understood. The objectives of this study were to (1) compare small mammal species richness, similarity, and diversity between paired burned and unburned treatment plots, and (2) assess long-term trends of small mammal community responses to burning. Five paired burned/unburned sites having similar vegetation, soils, elevation, and annual precipitation were...
Distribution, movements, and habitat use of 10 wild adult razorback suckers (Xyrauchen texanus) were examined in Lake Mohave, Arizona-Nevada, from November 1994 through July 1997. Movement rates (0.00?17.35 km d?1) and ranges (x?= 39 km) were similar to those for riverine populations. All study fish returned to spawning sites used in previous years, but they also visited other spawning areas. Spawning females were significantly (P = 0.031) more active than males (480 vs. 87 m d?1) and moved substantial distances between spawning sites during peak reproduction (1?28 February). Fish became most active (m d?1, km month?1) after spawning and moved to areas known to support higher algal production. Fish were typically...
The pygmy rabbit (Brachylagus idahoensis) is a secretive, obligate sagebrush-steppe resident of the Intermountain West and is one of two rabbits in North America that digs its own burrows. Although the pygmy rabbit has a recorded home range of 0.21?67.9 ha in relatively high sagebrush cover (21%?36%), they spend much of their time within 30?100 m of a burrow system. Due to big sagebrush cover in preferred habitat and the secretive behavior of pygmy rabbits, it is often difficult to study this leporid through direct observation. We used remote cameras to document pygmy rabbit activity at burrow systems in south central Utah from 2006 to 2008. We analyzed photographs from remote cameras for daily and seasonal patterns...
The present distribution of the Mexican vole (Microtus mexicanus) is not entirely the product of post-Pleistocene forest fragmentation and extinction; recent dispersal also is indicated. Literature records further suggest that this phenomenon may reflect a general pattern of northward range expansion in many southwestern mammal species. Published in Western North American Naturalist, volume 52, issue 3, in 1992.
Blackbursh (Coleogyne ramosissima Torr.) is a dominant desert shrub in a distinct mid-elevations vegetation belt between creosote bush-bursage (Larrea tridentata-Ambrosia dumosa) shrubland below and big sagebrush-pinyon pine- Utah juniper (Artemisia tridentata-Pinus monophylla-Juniperus osteosperma) woodland above in the Mojave Desert. Seed germination patterns of blackbrush seeds collected from 2 elevations (1200 and 1550 m) in 5 mountain ranges within the blackbrush shrublands were investigated. Morphological features of blackbrush seeds, including weight, length, and width, were not significantly different (P > 0.05) among elevations and mountain ranges in the Mojave Desert. Germination of blackbrush seeds was...
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Much of western North America is dominated by dense, monotypic, late seral stands of big sagebrush (Artemisia tridentata Nutt.). These stands often have depauperate understories with limited species richness, diversity, and herbaceous cover. The National Park Service at Dinosaur National Monument, Colorado, is using both strategic and natural prescribed fire in Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis Beetle and Young) communi- ties to foster intra-community (α-scale) and landscape diversity. This study analyzed an accumulated foliar cover data set between paired burn and control areas on 6 different sites during the last 20 years. Across the monitoring period, mean total vegetation cover of...
Composite soil samples from 7 sites on San Nicolas Island were evaluated quantitatively and qualitatively for the presence of cyanobacteria and eukaryotic microalgae. Combined data demonstrated a rich algal flora with 19 cyanobacterial and 19 eukaryotic microalgal genera being identified, for a total of 56 species. Nine new species were identified and described among the cyanobacteria and the eukaryotic microalgae that were isolated: Leibleinia edaphica, Aphanothece maritima, Chroococcidiopsis edaphica, Cyanosarcina atroveneta, Hassallia californica, Hassallia pseudoramosissima, Microchaete terrestre, Palmellopsis californicus, and Pseudotetracystis compactis. Distinct distributional patterns of algal taxa existed...
Artemisia carruthii and A. frigida of the subgenus Artemisia and A. filifolia and A. spinescens of the subgenus Dracunculus all have chromosome numbers based on x = 9. Diploid (2n = 18) karyotypes of each species are composed of large, medium, and small chromosomes that are mainly metacentric and submetacentric. The individual karyotypes are similar but distinctive. Artemisia filifolia?s karyotype and chemistry is quite similar to that of Section Tridentatae, but A. filifolia has significant morphological differences with respect to the Tridentatae. Artemisia spinescens includes a tetraploid (2n = 36) population as well as diploid populations. Karyotypic analysis of a tetraploid A. spinescens suggests that it is...
Recovery rates of cyanobacterial-lichen soil crusts from disturbance were examined. Plots were either undisturbed or scalped, and scalped plots were either inoculated with surrounding biological crust material or left to recover naturally. Natural recovery rates were found to be very slow. Inoculation significantly hastened recovery for the cyanobacterial/green algal component, lichen cover, lichen species richness, and moss cover. Even with inoculation, however, lichen and moss recovery was minimal. Traditional techniques of assessing recovery visually were found to underestimate time for total recovery. Other techniques, such as extraction of chlorophyll a from surface soil and measurement of sheath material accumulation,...
Biological invasions are one of the greatest threats to native species in natural ecological systems. One of the most successful invasive species is Bromus tectorum L. (cheatgrass), which is having marked impacts on native plant communities and ecosystem processes. However, we know little about the effects of this invasion on native animal species in the Intermountain West. Because ants have been used to detect ecological change associated with anthropogenic land use, they seem well suited for a preliminary evaluation of the consequences of cheatgrass-driven habitat conversion. In our study, we used pitfall traps to assess ant community assemblages in intact sagebrush and nearby cheatgrass-dominated vegetation....
Soil compaction from human trampling, biking, and off-road motor vehicle traffic was quantitatively investigated in a blackbrush (Coleogyne ramosissima) shrubland in Kyle Canyon of the Spring Mountains in southern Nevada. A significant difference was detected in soil compaction, bulk density, and percent pore space at a particular frequency of visits in each of 4 disturbance types. On average a single vehicle pass was equivalent to 10 human footprints. Ten and 100 footprints were equivalent to 1 motorcycle pass and 10 vehicle passes, respectively. Soil compaction is a product of increased bulk density and decreased pore space. The degree of soil compaction is a function of disturbance type and visit frequency when...
Benthic macroinvertebrates from four habitat types (river channel, ephemeral side channel, river backwater, and seasonally inundated wetland) were examined from the Green River at the Ouray National Wildlife Refuge, Uintah County, UT, June-August 1991. For major taxa (Nematoda, Oligochaeta, Diptera: Ceratopogonidea, and Chironomidae) were quantified. Chuster analysis of densities showed that habitat types with comparable flow conditions were the most similar. Highest to lowest overall benthic invertebrate densities of the four habitats were as follows: ephemeral side channel, river backwater, seasonally inundated wetland, and river channel. Nematodes were the most abundant taxon in all habitat types and sample dates...
Twelve wild adult Colorado pikeminnow (Ptychocheilus lucius), captured in the tailwaters of Taylor Draw Dam on the White River, Colorado, were implanted with radio transmitters and their movement patterns monitored from 1992 to 1994. The spawning migration of these fish was extensive. In 1993, the only full year of the study, the fish migrated an average of 658 km from the White River to spawning sites in the Yampa or Green rivers and back to the White River. Eight of these fish were translocated in the river upstream of the dam in April 1993. These fish and the 4 others below the dam remained in the river until May 1993. All 12 had migrated down the White River to spawning sites in the Green and Yampa rivers by...
We conducted a trapping survey of small mammals along an elevational gradient in the La Sal Mountains and documented 4 species of shrews (Sorex), the largest number inhabiting any mountain range in Utah. Sorex palustris was restricted to very moist microhabitats near open water at mid- to high elevations where it was relatively common. Occurring in nearly all habitats across the entire sampling gradient, S. monticolus was the numerically dominant small mammal at many sites. Sorex nanus, a new record for the La Sals, was found in areas of rockfall at high elevations and in a rocky wash at mid-elevation. Sorex cinereus, a new record for southeastern Utah, was recorded at a single high-elevation locality. Most localities...
map background search result map search result map Changes in the distribution and status of sage-grouse in Utah Vegetation response to prescribed fire in Dinosaur National Monument Fire effects on small mammal communities in Dinosaur National Monument Persistence of subalpine forest--meadow ecotones in the Gunnison Basin, Colorado Collection of Asian tapeworm ( Bothriocephalus acheilognathi ) from the Yampa River, Colorado Vegetation response to prescribed fire in Dinosaur National Monument Fire effects on small mammal communities in Dinosaur National Monument Collection of Asian tapeworm ( Bothriocephalus acheilognathi ) from the Yampa River, Colorado Persistence of subalpine forest--meadow ecotones in the Gunnison Basin, Colorado Changes in the distribution and status of sage-grouse in Utah